The present invention relates to a method and system for preparing plastic material loads for supply to a molding press.
A common practice nowadays in the vehicle body component industry is to mold parts from plastic sheet material, such as heat-setting fiberglass-reinforced polyester resin known as sheet molding compound (hereinafter referred to as "SMC"), which is usually supplied in rolls. For each production part, the press is loaded with a number of sheets cut off the roll, and the size of which must correspond accurately to the part being produced. For each production part, known systems provide for cutting off two sheets, the second of which varies in size so that the total size of the two sheets approximately equals that required for the part being produced. A major drawback of such systems is the poor or inconsistent quality of the parts produced, due to inevitable errors in cutting and positioning the sheets. Moreover, a good deal of time and effort is expended for calculating and measuring the size of the second sheet, and positioning it accurately in relation to the first sheet.